TY - JOUR
T1 - Blood-to-Retina Transport of Fluorescence-Labeled Verapamil at the Blood-Retinal Barrier
AU - Kubo, Yoshiyuki
AU - Nakazawa, Ayumi
AU - Akanuma, Shin ichi
AU - Hosoya, Ken ichi
N1 - Publisher Copyright:
© 2018, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - Purpose: To investigate the blood-to-retina verapamil transport at the blood-retinal barrier (BRB). Methods: EverFluor FL Verapamil (EFV) was adopted as the fluorescent probe of verapamil, and its transport across the BRB was investigated with common carotid artery infusion in rats. EFV transport at the inner and outer BRB was investigated with TR-iBRB2 cells and RPE-J cells, respectively. Results: The signal of EFV was detected in the retinal tissue during the weak signal of cell impermeable compound. In TR-iBRB2 cells, the localization of EFV differed from that of LysoTracker® Red, a lysosomotropic agent, and was not altered by acute treatment with NH4Cl. In RPE-J cells, the punctate distribution of EFV was partially observed, and this was reduced by acute treatment with NH4Cl. EFV uptake by TR-iBRB2 cells was temperature-dependent and membrane potential- and pH-independent, and was significantly reduced by NH4Cl treatment during no significant effect obtained by different extracellular pH and V-ATPase inhibitor. The EFV uptake by TR-iBRB2 cells was inhibited by cationic drugs, and inhibited by verapamil in a concentration-dependent manner with an IC50 of 98.0 μM. Conclusions: Our findings provide visual evidence to support the significance of carrier-mediated transport in the blood-to-retina verapamil transport at the BRB.
AB - Purpose: To investigate the blood-to-retina verapamil transport at the blood-retinal barrier (BRB). Methods: EverFluor FL Verapamil (EFV) was adopted as the fluorescent probe of verapamil, and its transport across the BRB was investigated with common carotid artery infusion in rats. EFV transport at the inner and outer BRB was investigated with TR-iBRB2 cells and RPE-J cells, respectively. Results: The signal of EFV was detected in the retinal tissue during the weak signal of cell impermeable compound. In TR-iBRB2 cells, the localization of EFV differed from that of LysoTracker® Red, a lysosomotropic agent, and was not altered by acute treatment with NH4Cl. In RPE-J cells, the punctate distribution of EFV was partially observed, and this was reduced by acute treatment with NH4Cl. EFV uptake by TR-iBRB2 cells was temperature-dependent and membrane potential- and pH-independent, and was significantly reduced by NH4Cl treatment during no significant effect obtained by different extracellular pH and V-ATPase inhibitor. The EFV uptake by TR-iBRB2 cells was inhibited by cationic drugs, and inhibited by verapamil in a concentration-dependent manner with an IC50 of 98.0 μM. Conclusions: Our findings provide visual evidence to support the significance of carrier-mediated transport in the blood-to-retina verapamil transport at the BRB.
KW - blood-retinal barrier
KW - lysosomal trapping
KW - neuroprotectants
KW - organic cation transport
KW - verapamil
UR - http://www.scopus.com/inward/record.url?scp=85043699160&partnerID=8YFLogxK
U2 - 10.1007/s11095-018-2384-7
DO - 10.1007/s11095-018-2384-7
M3 - 学術論文
C2 - 29532174
AN - SCOPUS:85043699160
SN - 0724-8741
VL - 35
JO - Pharmaceutical Research
JF - Pharmaceutical Research
IS - 5
M1 - 93
ER -